The subject matter of this disclosure relates generally to switched reluctance motors, and more particularly, to a control method for reducing torque ripple in switched reluctance motors.
The switched reluctance motor (SRM) is a simple and robust electric machine that can be attractive for a number of applications due to the absence of permanent magnets or windings on the rotor. A limiting factor in the application of SRMs is the torque ripple produced by the machine as torque production is passed from one phase to another. In the past, it was possible to reduce torque ripple produced by the SRM only over a limited speed range and with the use of sophisticated current regulators.
Control of the SRM is complicated by the spatial and magnetic nonlinearities inherent to the machine. The traditional approach to SRM excitation is to design the current waveform for each phase, and implement those current waveforms independently of one another. This requires an inverter structure that is different from the inverter structure that is used for other types of AC machines, such as permanent magnet synchronous and induction machines.
In view of the foregoing, there is a need for a method of reducing torque ripple in switched reluctance motors that facilitates the use of a standard inverter topology, combined with a simpler current regulation algorithm.